package com.example.emos.wx.config.xss;

import cn.hutool.core.util.StrUtil;
import cn.hutool.http.HtmlUtil;
import cn.hutool.json.JSONUtil;

import javax.servlet.ReadListener;
import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.io.*;
import java.nio.charset.Charset;
import java.util.LinkedHashMap;
import java.util.Map;

public class XssHttpServletRequestWrapper extends HttpServletRequestWrapper {

    public XssHttpServletRequestWrapper(HttpServletRequest request) {
        super(request);
    }

    @Override
    public String getParameter(String name) {
        String value = super.getParameter(name);
        if(!StrUtil.hasEmpty(value)){
            value = HtmlUtil.filter(value);
        }
        return value;
    }

    @Override
    public String[] getParameterValues(String name) {
        String[] values = super.getParameterValues(name);
        if(values!=null){
            for (int i = 0; i < values.length; i++){
                String value = values[i];
                if(!StrUtil.hasEmpty(value)){
                    value = HtmlUtil.filter(value);
                }
                values[i] = value;
            }
        }
        return values;
    }

    @Override
    public Map<String, String[]> getParameterMap() {
        Map<String, String[]> parameters = super.getParameterMap();
        LinkedHashMap<String, String[]> map = new LinkedHashMap();
        if(parameters!=null){
            for (String key : parameters.keySet()){
                String[] values = parameters.get(key);
                for (int i = 0; i < values.length; i++) {
                    String value = values[i];
                    if (!StrUtil.hasEmpty(value)) {
                        value = HtmlUtil.filter(value);
                    }
                    values[i] = value;
                }
                map.put(key, values);
            }
        }
        return map;
    }

    @Override
    public String getHeader(String name) {
        String value = super.getHeader(name);
        if (!StrUtil.hasEmpty(value)) {
            value = HtmlUtil.filter(value);
        }
        return value;
    }

    @Override
    public ServletInputStream getInputStream() throws IOException {
        InputStream in = super.getInputStream();
        InputStreamReader reader = new InputStreamReader(in, Charset.forName("UTF-8"));
        //创建一个字符串缓冲对象
        BufferedReader buffer = new BufferedReader(reader);
        //字符串处理
        StringBuffer body = new StringBuffer();
        String line = buffer.readLine();
        while(line != null){
            body.append(line);
            line = buffer.readLine();
        }
        buffer.close();
        reader.close();
        in.close();

        //将json字符串转换为map集合
        Map<String,Object> map = JSONUtil.parseObj(body.toString());
        Map<String,Object> result = new LinkedHashMap<>();

        for(String key : map.keySet()){
            Object val = map.get(key);
            if(val instanceof String){
                if(!StrUtil.hasEmpty(val.toString())){
                    result.put(key, HtmlUtil.filter(val.toString()));
                }
            }
            else {
                result.put(key,val);
            }
        }

        //将字符串map集合转换为字符串
        String json = JSONUtil.toJsonStr(result);
        ByteArrayInputStream bain = new ByteArrayInputStream(json.getBytes());
        return new ServletInputStream() {
            @Override
            public int read() throws IOException {
                return bain.read();
            }

            @Override
            public boolean isFinished() {
                return false;
            }

            @Override
            public boolean isReady() {
                return false;
            }

            @Override
            public void setReadListener(ReadListener readListener) {

            }
        };
    }
}
